More recently, replay was also identified in the hippocampus of awake animals (Foster and Wilson, 2006 and Carr et al., 2011). Such replay of learning-related activity stored long-term could drive

structured spontaneous activity in the sensory cortex (Ji and Wilson, 2007). In summary, our approach with chronically implanted μECoG arrays allowed us to identify the sensory map and probe the spatiotemporal dynamics of intrasulcal auditory cortical areas in awake monkeys. This led to the finding that spontaneous activity reflected the functional architecture of the auditory cortex along nearly the entire supratemporal plane. The experimental and analytical methods that led to the finding holds promise for advancing our understanding of how the PD-1/PD-L1 inhibitor 2 spectral and temporal features of highly complex sounds (Bendor and Wang, 2008), such as species-specific vocalizations (Poremba et al., 2004, Petkov et al., 2008, Kikuchi et al., 2010 and Perrodin et al., 2011), are processed in the auditory cortex.

Two adult rhesus monkeys (Macaca mulatta) weighing 5.5–9 kg were used. All procedures and animal care were conducted in accordance with the Institute of Laboratory Animal Resources Guide for the Care and Use of Laboratory Animals, and under an approved National Institute of Mental Health Animal Care and Use Committee protocol. The monkeys’ hearing ability was examined with distortion product otoacoustic emission (DPOAE); the results suggest that both monkeys had normal to near-normal peripheral hearing binaurally. We custom-designed a microelectrocorticographic

Smoothened (μECoG) array to record BKM120 chemical structure field potentials from macaque auditory cortex (NeuroNexus Technolgies Inc., MI). The array is machine-fabricated on a very thin polyimide film (20 μm). Each array had 32 recording sites, 50 μm in diameter, on a 4 × 8 grid with 1 mm spacing (i.e., 3 × 7 mm rectangular grid). We implanted 4–5 μECoG arrays in each of two monkeys (monkey M, five arrays in the right hemisphere; monkey B, four arrays in the left hemisphere). Three of the arrays were placed on the supratemporal plane, a fourth was positioned over the parabelt on the lateral surface of the superior temporal gyrus (STG) adjacent to A1, and, in monkey M, a fifth array was placed on the lateral surface of STG just rostral to the fourth array (data gathered from the lateral-surface arrays are not reported in this paper). Monkeys were fasted for 12 hr before surgery and pretreated with an antibiotic (Ditrim, 24% solution, 0.1 ml/kg i.m.). On the day of surgery, the animal was sedated with ketamine (10 mg/kg i.m.) and anesthetized with isoflurane (1%–4% to effect). Throughout surgery, vital signs were monitored, including SpO2, and the animal was kept warm with a heating pad and hydrated (Ringer’s solution i.v.). Mannitol (30%, 30 cc i.v. over 20 min) was infused to reduce brain volume. Standard sterile neurosurgical procedures were used throughout.